Treatment for gases given off in the destructive distillation of coal &amp;c.



U IHIEnsT TEs PATENT, OFFICE."

eusrnvninqnnsrocx, or nAnmAUsEN-nunn, ennmnnm TREATMENT OF GASES GIVEN OFF .THE DESTRUCTIVE DISTILIIATION OF COAL,

No Drawing.

d ll uiiwm it concern:

Be it known that I, GUSTAV 'Hmmsme a subject of the Emperor of Germany, residing in Dahlhausen-Ruhr, Westphalia, Prussia, Empire of Germany, have invented a certain new and useful Improvement in" the Treatment, of.Gases Given Ofi' the Destructive Distillation of Coal, Llgmte,

Peat, and the Like, of which the following moving some of the constituents of such the tar ifiefeto fhre it has been proposed, in the German Patent No. 2Q3,254, to wash the tar out of the hot gases byispraying tarinto the,

gases, and to recover the ammonia by passmg-the gases through anacidbath With such atfiqiattme'nt', however,- I have found theta poftionof the fixed ammonia, chiefly ammonlum chlorid, is taken up by :the washin tar. This can not be washed out of diy mixing gas liquor with the latter to thereby; permit the recoveryof the ammon'ia subsequently passing the gas liquor through the acid bath. I haverdiscovered, however, that by washing the gases a second time, after they pass through the.

acid bath; with the wash tar of the first washing operation, as by spraying the wash tar in tothe. gases the ammonia in the wash tar? washed outf by the water vapors condensing from the gases, and may thereby berecovered, This washin of the ammonia out'of-the tar maybe fac" tated by the admixture of gas liquors with'the tar, and also by evaporating gas liquor and mixing the resultant vapors with the gases} after the gases have passed through the acid bath.

A second advantageous result had by reason of the second washing is the dissolving of the naphthalene out of the gases by the tan, The naphthalene thus removed from the gases has heretofore often become annoying when thetar has been eliminated at a high temperature. v The second washing of the ases, as described, may, by a suitable regulation of the relative quantities of gases and'tar and'of- Specification of Letters Patent. Application filed September 19, 13.10. ,Serial No. 582,662.

Patented-June 6, 1911 "the temperature conditions, be caused to resultin the absorption from the gases of the vaporous illuminants contained therein, such as benzol and toluol vapors and the like, and their ultimate recovery if itis not desired to use the gases for illuminating purposes. If it is desired to use the gas for illuminating purposes, the conditions may be so regulated, however, that the second washing will not remove the illuminants from the gases..-

When 'it'is desired to remove the illuminants, the wash tar for the second washing should be as cool as is practically possible,

with the cooling medium (cooling water) available. To augment'the absorption of the illuminants, tar oils may also be added to the washing tar.- By this procedure the bulk, if not all, of the illumina'nts may be extracted from the gases. By subsequently heating the washing tar to the temperature required for the first washing operation,

which may be up to seventy or. eighty de. grees centigrade, a considerable portlon of.

the absorbed hydro-carbons, may be evaporated, especially if the reheating of the tar is done in a current of gas or steam. The evaporated hydro-carbons may be recovered and utilized in various ways well known to those skilledjin the alt, a

Where it is not'desired to impairthe illuminating value of the gas by the second washing this may be avoided by increasing the temperature of the washing tar, and de-.,

creasing its relative volume as compared with the conditions employed when it IS desired to have the 'illuminants absorbed.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. The method of treating the hot gas re-- sulting from the destructive distillation of coal, lignite, peat and the like, which consists in washin the gas with tar, then passing the gas th ough an acid bath, andthen washing the gas a second time with the washing tar of the first washing operation.

- 2. The method of treating the-hot gas resultin coal, lignite, peat, and the like, which confrom the destructive distillation of sists inwashing the gas with tar, then passing the gas through an acid bath, and then washing the. gas a second time with the washing tar. of the first washing operation 'mixed with gas liquor.

' 3'. The meth'btl of treating the hot gases ing the gas a seeonti time with thewashing resultin from the destructive distillation tarof the first operation.

01" coal, peat, and the like, which conv v 'sists in washing the gas with tar, then pass- GUSTAV HILGENSTOCK' 5 ing the gas through an acid bath', and then Witnesses: admixing with the gas the vapors or steam WILHELMINE SOHXFEB, evaporated from gas 1iquor, and'then wash- ANNA Rnmnow. 

